INS Sindhurakshak (S63): exploring general characteristics and operational history

A key component of the Indian Navy, the Kilo-class submarine INS Sindhurakshak made significant contributions to the 1999 Kargil War. In 2013, following major renovations, it encountered difficulties, including a storm in the Mediterranean and a deadly explosion in Mumbai, which resulted in its sinking.

Named after the Sanskrit phrase “Protector of the Seas,” INS Sindhurakshak was an Indian Navy diesel-electric submarine of the Kilo-class 877EKM or Sindhughosh-class. It was the ninth of the ten Kilo-class submarines in the Indian Navy’s fleet when it was put into service on December 24, 1997.

On June 4, 2010, an important milestone was reached when the Indian Defence Ministry and the Zvezdochka shipyard signed a US$80 million contract for the overhaul and thorough upgrade of INS Sindhurakshak. The objective of this restoration project was to increase the submarine’s operational lifespan and improve its capabilities. After undergoing these improvements, the submarine left Russia and arrived back in India in May or June of 2013.

The building of INS Sindhurakshak began in 1995 and was carried out at the Admiralty Shipyard in Saint Petersburg, Russia. The submarine, which was launched in June 1997 and delivered to India in December of the same year, significantly increased the Indian Navy’s maritime capabilities. Its position as a powerful member of the nation’s naval fleet highlighted the vessel’s strategic significance.

General Characteristics:

The INS Sindhurakshak (S63) is a Sindhughosh-class submarine with a displacement of 3,076 tonnes underwater and 2,325 tonnes on the surface. The submarine’s propulsion system consists of two 2,720 kW diesel-electric engines, a 4,400 kW motor, two 152 kW auxiliary motors, and a 97 kW economic speed motor. Its dimensions are 72.6 metres in length, 9.9 metres in beam, and 6.6 metres in draught.

The INS Sindhurakshak has a top speed of 10 knots, a snorkel speed of 9 knots, and a submerged speed of an astounding 17 knots. When in snorkel mode, the submarine can go 9,700 km at 7 knots, and when submerged, it can travel 640 km at 3 knots. With a maximum stay of 45 days, the ship can carry 52 people, including seven officers and 61 ratings.

Equipped with an array of armaments, the INS Sindhurakshak can operate at a maximum depth capability of 300 metres and an operational depth of 240 metres. This comprises the Type 53-65 passive wake-homing torpedoes, the 3M-54 Klub-S anti-ship and land-attack missiles, the 9M36 Strela-3 (SA-N-8) surface-to-air missile, and the TEST 71/76 anti-submarine active-passive homing torpedoes. The submarine also can carry 24 DM-1 mines instead of torpedo tubes. 

Operational History:

Stationed near Karachi, Pakistan, the INS Sindhurakshak was instrumental in the 1999 Kargil War. Following that, it made history in 2006 when A. P. J. Abdul Kalam, the country’s president at the time, became the first head of state to set sail in a submarine. Accompanied by Chief of Naval Staff Arun Prakash and under the command of Commander P S Bisht, President Kalam undertook a demonstration excursion while on deployment in Visakhapatnam, diving and sailing in the Bay of Bengal for a short while.

One sailor lost his life and two others were injured when a fire broke out on board the Sindhurakshak in Visakhapatnam in February 2010. The event was identified as the result of a hydrogen gas leak from a malfunctioning battery valve that exploded in the submarine’s battery compartment.

The submarine had a thorough overhaul, upgrade, and refurbishment in Russia after the fire damage. Completed in January 2013, the modifications featured enhanced weaponry such as Club-S missiles, a new cooling system, an integrated weapon control system, and upgraded electronic warfare capabilities. Interestingly, this was the first Indian submarine to operate in an ice-covered environment.

When the Sindhurakshak was returning from the refurbishment in March 2013, it encountered strong storms in the Mediterranean Sea. The Egyptian Navy had to come to the submarine’s rescue to pull it to safety in Port Said.

The submarine sank at its Mumbai port on August 14, 2013, following explosions brought on by a fire, marking another tragic event. Explosion damage caused the submarine to sink although efforts were made to put out the fire. Many sailors lost their lives in the tragedy, and recovery operations indicated that human error and crew exhaustion played a part.

On Navy Day 2015, it was officially announced that the submarine would be decommissioned, contrary to early expectations of reviving the Sindhurakshak. The submarine was purposefully sunk in the Arabian Sea in June 2017 after being used for training marine commandos for a while. It was situated in 3000 metres of water. The INS Sindhurakshak had a mixed operating history, filled with both triumphs and tragic events that finally resulted in its decommissioning.